The starting point for this work are the so-called Extractos of the Royal Basque Society of the Friends of the Country (Real Sociedad Bascongada de Amigos del PaÃ­s), which was the institution mostly instrumental in promoting potato cultivation. The Extractos were texts dealing with advances in agriculture, and it was the bibliography that Palanca began with in order to produce this thesis, to which he has added all manner of provincial, judicial and diocesan documents of the three provinces of the Basque Country (Ãlava, Bizkaia and Gipuzkoa). The researcher took 1760 as the starting date of the study, since documents like those dealing with a lawsuit that took place in the Zuia valley as a result of the payment/non-payment of the potato tithe (1816) indicate that this crop was already present in the three territories (in Bilbao, in the Zuia Valley itself, and in Hondarribia) by the 1760s. As far as the end date is concerned, 1860 has been taken because by then documents already existed from which it is possible to deduce that potato sowing was widespread in the three provinces.

The tithe

To analyse how potato growing evolved in the three territories, one of the indicators which Palanca has taken as a basis was the payment of the tithe; this proved to be particularly useful when dealing with Ãlava. "People had to pay a tithe as soon as enough was cultivated to consume and to eat, four or five years after starting to grow it," he explains. So its expansion in this territory is known to have taken place rapidly from 1760 onwards, since the church tithe barn was receiving potato tithes from all over Ãlava, except from the Rioja area of Ãlava, by the end of the 18th century.

Other documents have turned out to be useful in showing that in the case of Gipuzkoa there is evidence of the presence of the potato in the border municipalities of IrÃºn and Hondarribia around 1764; and a second nucleus is located in Gabiria, Bergara and Legazpi around 1770. By 1840, the potato had spread all over Gipuzkoa except in the Tolosa area. In Bizkaia it was being sown in some spots in Bilbao and its environs around 1774-77, by 1830 it had spread all over the province and according to data of 1859, its production was a feature in the Balmaseda area, while there was little in the Durango area.

"During the Peninsular War, in Gipuzkoa for example, the French troops dug up the potato fields in search of potatoes because there was quite a lot of hunger. So the Basques saw them eating the potatoes and suffering no adverse effects; they did not get ill and they put on weight," explains Palanca. This appears to have helped the people of Ãlava to see the light: "In Bizkaia and in Gipuzkoa they had the sea, but Ãlava was totally agricultural; there they depended on the sky. As the potato goes down to the subsoil and remains unaffected whether it rains or hails, that is the area where it saw a considerable increase. They saw that it was a crop that could be used to feed people, and as it was in the subsoil, it was able to withstand unfavourable weather conditions."

In any case, it is clear that at that time it was in Ãlava where potato consumption became most widespread among humans. In Bizkaia and Gipuzkoa it seems to have been used more to feed animals. Palanca also explains that this tuber was also used for medicinal purposes. The most recommended uses were as a poultice for burns and growths as well as a prevention and cure for scurvy.